This haggard and expressive figure is a late work by Donatello, who in 1457 delivered the bronze to Siena Cathedral for their Chapel dedicated to that saint. The right arm was however missing, and it is evident, from the awkwardness of what must be a later replacement arm, that it was not designed to point upwards at this angle.

Donatello (1386-1466) was the most imaginative and versatile Florentine sculptor of the early Renaissance, famous for his rendering of human character and for his dramatic narratives. He achieved these ends by studying ancient Roman sculpture and amalgamating its ideas with an acute and sympathetic observation of everyday life. Together with Alberti, Brunelleschi, Masaccio and Uccello, Donatello created the Italian Renaissance style, which he introduced to Rome, Siena and Padua at various stages of his career. He was long-lived and prolific: between 1401 and 1461 there are 400 documentary references to him, some for nearly every year. However, there is no contemporary biography, and the earliest account, in Vasari’s Vite (1550), is confused.

Plaster casts were especially sought after during the 19th century, when reproductions of great works of sculpture and architecture were thought crucial for the training of artists. A separating substance was applied to the surface of the work to be reproduced, and a plaster mould made from that. The mould would then be used to make any number of additional plaster copies. These were often sold to artists, and later in the century to art colleges for study purposes.